Air register control



Nauw@ E. H. PEABODY AIR REGISTER CONTROL Filed Jan. 19, 1939 In m u y A. 4 ,l u i ql Illll r IlV www, SN www @N mm Q www l Aug. \6, 1940.

'Patented ug. 6,1940

PATENT OFFICE AIR REGISTER CONTROL Ernest H. Peabody, New York, N. Y., assignor to Peabody Engineering Corporation, New York, N. Y., a corporation of New York Application January 19, 1939, Serial No.' 251,678y

1 Claim.

This invention relates to fuel burners and "more particularly to burners ofthe type having fuel supply means for liquid, gaseous or pulverized fuel and an air register supplying air for com-- bustion purposes.

The invention may be applied, for example, to variable capacity atomizing burners of the type commonly known as the Peabody wide range burner. This type of burner, in general, comprises an atomizer for liquid fuel, having a whirling chamber in which the fuel is caused to rotate rapidly to set up centrifugal forces which break up or atomize the fuel as it is released `from the atomizer tip. In one embodiment the capacity is controlled by withdrawing a selectedl return portion of the fuel from the whirling chamber or other appropriate part of the atomizer. By varying the pressure in the return'line the quantity of fuel atomized may be adjusted as desired. Such a burner and controls therefor is shown and described more in detail in U. S. Patent to E. H. Peabody, N0. 1,628,424, dated May 10, 1927.

A further development is shownin U. S. Patent to Graham et al., No. 1,824,952, dated 'Sept 29, 1931, which describes a system for maintaining a controlled pressure drop across the tangential slofsysupplying fuel to the whirling chamber so as'fto improve the operating characteristics of the burner atvarious loads. In this embodiment the pressure in both the supply and return lines varies as a function of the operating capacity of thel atomizer. The Graham et al. patent points out that the operating capacity of the burner is dependent upon the oil pressure in the tip and that the form of the spray is dependent upon the centrifugal force'produced by the rapid whirling motion of the oil in the whirling chamber. The

latter factor is dependent upon the velocity of the.

` oil entering the tip which is determined by the pressure drop across the tangential slots. In the Graham system, the pressure drop across the slots is maintained substantially constant by a control of the pressure diiferential between the supply and return lines. The pressure in the whirling chamber being dependent upon the pressure in the return line accordingly varies as a function of the pressures in both the return and supply lines. The pressure in either of these linesl accordingly constitutes a measure of the operating capacity of the burner.

The air register, as shown in Patent 1,628,424

above mentioned, may be provided with a'peripheral set of adjustable air doors which are pivotally mounted for adjustment in unison so as to vary the quantity, velocity and direction of the air. A further embodiment of air register construction is shown in application Serial No. 196,- 878 for Fuel burners, filed March 19, 1938,'in which a set of radial dempers are provided to advmit controlled quantities of airr around the axis 5 ofthe burner to be combined with the rotating mass of air admitted through the peripheral doors and to improve the combustion characteristics.

It has been found that for most emcient operation the quantity velocity and direction of air 10 supplied to the burner through the air. register should bear a denite relationship to the operating capacity of the atomizer and the present invention accordingly has for an object to provide novel and improved means for adjusting the air l5 register to fulfill these conditions.

Another object is to provide means responsive to the fuel consumption oi the burner to control the air supply.

Another object is to provide means responsive to changes in pressure in either thefuel supply line or the fuel return line to actuate the air register doors.

. Another object is to provide, in a mechanismof the above type, means to adjust the air doors as ya predetermined function of the operating capacity of the burner.

A further object is to provide automatic means for effecting lthe above adjustments.

A still further object is to provide remote controlled means for adjusting the air doors of an air register. v Another object is to provide a burner of the type above indicated, having novel and improved operating characteristics and details of construction.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

Althoughthe novel features which are believed 4.0 to be characteristic of this invention will be more particularly pointed out in the claim appended hereto, the invention itself will be better understood by referring to the following description, taken in connectionl with the accompanying drawing, in which a specific embodiment thereof hasy been set forth for purposes of illustration.

In the drawing:

Fig. lis a. longitudinal section through a burner constructed ln accordance with the present invention.

Fig. 2 is a transverse section taken along the line 2-2 of Fig. 1.

Fig. 3 is an enlarged partial sectional view of 5 5 forming the front wall of the furnace.

one form of atomizer which may be embodied in the burner of Figs. 1 and 2, and

Fig. 4 is a diagrammatic view showing typical control lines.

In the following description and in the claims certain lspecincf terms are used for. convenience in referring to the various details-of the invention. It is to be understood, however, that these terms are to be given as broad an interpretation as the state of the art will permit. I,

Referring to the drawing more in detail, theinvention is shown, for purposes of illustration only,

released from the orince 59 atomization takes place. A controlled quantity of the fuel is withas applied to an air register of the type described in application Serial No. 196,878 referred to above. 'Ihe construction comprises, in general, an air register I0 having a plurality of air doors I'l arranged peripherally thereof and journalled on spacing sleeves I2a which are secured by rods I2 between a front ring I4 and an annular back plate I5. The back plate I5 is secured, as by bolts I6, toa plate I1. This plate I1 is secured to or mounted adjacent a refractory wall I8 A ring of refractory blocks I9, forming the burner throat, may be secured in the wall I8, as by bolts 20.

Each air door II is provided with a slotted arm 25 engaging a pin 26 mounted in an adjusting ring 21..; The adjusting ring 21 is journaled on the front ring I4 and may be held in position by suitable means, such as clips 28. The air register is shown as provided with a front cover comprising vanes 30 rigidly mounted between a hub 3| and a peripheral ring 32, which is secured by suitable means such as by bolts 33, to the front ring I4. The vanes 30 may be inclined to impart a rotating motion to the air passing axially therebetween into the burner throat. For controlling vthe quantity of air passing between the vanes 30,

there is shown a plurality of dampers 35 which drawn through the passages 6I and is returned through the return pipe 55. The amount so returned controls the operating capacity of the nozzle vas more fully set forth in the Patent No. 1,628,424, above referred to. In some instances the fuel return may be omitted and the operating capacity controlled by suitable variation of the fuel supply pressure.

The burner barrel also carries a. diiluser 65 which controls the passage of air to the burner throat and provides for the desired mixture thereof with the atomized fuel.

The fuel may be supplied through a line 10, Fig.

4, to the passage 56, Fig. 3, and may be withdrawn from the pipe by means of a return line 1 I, suitable regulating means being provided,

such as valves 12 and 13, to control the uid are pivotally mounted on rods 36, supported at their outer ends by the ring 32 and at their inner ends by a flange 31 carried by the hub 3l. The inner ends of the rods 36 are shown as bent to provide adjusting levers 36 by which the pivotal position of the dampers is controlled. A sleeve 49 is mounted within the hub 3I and suitably secured as by a set screw 4I. This sleeve is rigidly burner.

attached'by suitable means to a front plate 42, having a hub 43. A baiile 45 may be lmounted in spaced relationship'to the wall I8 so as to form a wind box through which air is supplied to the air register. This baille 45 may be provided with' an opening 46 of sucient size `to permit the entire burner to be removed therethrough andV which is normally closed by a plate 41 extending between the baille 45 and the front plate 42 of the 53, threaded on the barrel 5l). The plug 5I may be provided with a central flange 54 which fits over a return pipe 55 concentric with the burner barre1 50, and spaced therefrom to provide an annular supply `passage 56. 'I'he tip 52 is provided with a chamber 51 communicating with the supply passage 56 by tangential passages 56 which are arranged to supply the fuel tangentially to the chamber 51 whereby the fuel is caused to whirl rapidly therein. The chamber 61 is tapered pressure in said lines. In an arrangement of this character, the fluid pressure in the supply line 10, for example, may be held constant and the operating capacity of the burner may be controlled by regulating the valve 13 in the return line 1 I, thereby varying the pressure in the return line and the quantity of fuel which is withdrawn from the atomizer tip, or the return line may be omitted or the fuel return pressure may be held constant, in which case the operating capacity may be controlled by varying the fuel supply pressure.

In certain instances it may be desirable to maintain a substantially constant pressure difference between the supply and return lines. This may be accomplished by the provision of a valve 14 of the. type described more in detail in Patent No. 1,824,952, referred to above, which varies the pressure in the supply line 19 in accordance with variations in pressure of the return line 1I or vice versa. In this system the operating capacity may be adjusted by controlling either the valve 12 or the valve 13. The construction thus far described is set forth more. in vdetail in the patents and application above referred to. Consequently, only so much thereof has been set forth herein as is necessary to anV understanding of the present invention.

The invention is not limited to the specific burner construction described above for purposes of illustration, but may be applied to any burner for liquid, gaseous or pulverized fuel or comblnations thereof, such as those shown in U. S. Patents 1,671,494 to C. R. Stewart, dated May 29, 1928, 1,790,395 to S. T. Warner, dated Jan. 27, 1931, and 1,865,983 to S. T. Warner, dated July 5, 1932. In the above burners the gas may also be admitted peripherally if desired. The term atomizer, as used herein, is intended to include any of the above types of burner.

, 'I'he present invention utilizes the variable yfuel now to control the position of the air doors II and of the dampers V36. In the embodiment shown, this is; accomplished by l providing a sleeve I6 which is rotatably mounted on the sleeve 46 and carries an arm 6I provided with a pin 82' engaging a slot 63 in an arm 64 which is secured to a shaft l5. The shaft 85 is yjournalled 75 in a block 86 attached by suitable means, such asbolts 86a, to the front ring Il and carries at its free end a lever- 8`| provided with a slot 88, in which a pin 09 is seated. The pin 89 is carried by the ring 21, the arrangement being such that rotation of the sleeve 80 causes a corresponding rotation of the ring 21, thereby, through the 'pins 28 and arms 25, actuating the air doors The sleeve 80 is also provided with a hub 90 having a plurality of axial slots 9| which engage the levers 38 so that rotation of the sleeve 80 causes rocking movement of the levers 38 and thereby controls the position of the dampers 35. This particular operating linkage may, of course, be,

varied as desired to obtain unitary adjustment of the air doors and dampers or independentr adjustment may be provided. A specific embodiment has been shown for illustration only` For actuating the sleeve 80 there is provided a uid pressure motor, such as a cylinder having a piston |0| therein attached to a piston rod |02 which extends rearwardly from said cylinder and' carries a pin |03 which engages a helical slot |04 in the sleeve 80. The piston |0| is held forwardly-by a spring |05 seated Within the cylinder |00. Fluid pressure is supplied to the cylinder |00 by a-pipe |06 for the purpose of controlling the position of the piston |0|, which, in

turn, by means of the pin |03 and the slot |04,

controls the rotational position of the sleeve 80 and thereby effects adjustment of the air doors and of the dampers 35. The pin and slot may be replaced by a cam connection or by other linkage means to effect adjustment of the sleeve by the operation of the uid pressure motor and the cylinder may be mounted transversely to the burner axis if desired. Furthermore, other types of fluid pressure motors, such as a diaphragm motor or expansible bellows, may be employed.

The pipe |06 may be connected to the supply line 'l0 and the return line 1| through valves ||0 and respectively, so that communication can be established with eitherof said lines by suitable actuation of said valves. The arrangement is such that an increase in pressure in the fuel supply or fuel return line, as the case may be, which represents an increase in the operating capacity of the atomizer, causes a corresponding increase in the fluid pressure supplied to the cylinder |00 and thereby actuates the air doors II and dampers 35 in a direction to increase the supply of air. The pipe |06 may be connected to only one of the' lines 'l0 and 1 I, in which event the valves ||0 and may be omitted.

It is to be understood that the shape of the slot |04 and the relationship thereof to the plston rod |02 is such that the variation in air supply corresponds to the variation in requirements at the various operating capacities vof the burner. This may. for example, represent a straight line variation with the quantity of air varying directly as the quantity of fuel burned. The shape ofthe slot |04 must, however, take into consideration the relationship between the fuel pressure and the operating capacity and also the relationship between the annular position of the sleeve 80 and the quantity of air supplied through the air register.

It will be understood that the'present invention is not limited to this specific construction of air register and burner. The air doors may be arranged in the form of a cylinder or in certain instances may be arranged radially. In certain instances the dampers 35 and vanes '30 may be omitted provided the atomizer is so positioned with respect to the air doors that the proper mixture of air for combination purposes is thus obtained. Suitable manual adjustment means, such as a handle (not shown), may be provided for manually setting or adjusting the air doors and dampers as may be required. The invention may be applied to any desired type of air register wherein a variable air flow is required. Such air register may or may not be incorporated in a burner.

It is also to be understood that the fluid pressure for actuating the piston |0| may be obtained from either the supply line or the return l-ine ina constant differential system, or may be obtained from the return line in a system operating at a substantially constant supply pressure and a variable return pressure, or from the supply line in a system operating at constant re'- turn pressure or in a non-return system. In certain instances the fluid pressure supply to the cylinder |00 may be taken from an independent source and may be controlled manually.

Although a specific embodiment of the invention has been shown and described for purposes of illustration, it is to be understood that various changes and modifications may be made therein as will readily appear to a person skilled inthe art. The invention is only to be limited in accordance with the following claim.

What is claimed is:

A fuel burner comprising an atomizer of the variable return type having a tip provided with a whirling chamber having a discharge orifice, tangential slots to supply fuel to said chamber, a supply conduit to supply fuel to said slots, a

return conduit connected to withdraw fuel from said tip, means for maintaining a controlled pressure differential between said conduits, means for adjusting the fuelpressure in one of said conduits to thereby vary the operating capacity of the burner, an air register having adjusting means to control the quantity, velocity and direction of air supplied to said burner for combustion purposes, and pressure responsive means actuated by the fuel pressure in one of said conduits to eil'ect a corresponding adjustment of said register adjusting means so as to maintain a predetermined relationship between the operating capacity of the atomizer and the quantity, velocity and direction of the air supplied thereto.

- ERNEST H. PEABODY. 

